Peter van Inwagen distinguishes the General Composition Question (GCQ), which is to give necessary and sufficient conditions for the claim that the xs compose y without mereological vocabulary, from the Special Composition Question (SCQ), which is to give non-mereological necessary and sufficient conditions for the claim that there is a y such that the xs compose y again without mereological vocabulary. He thinks that he can answer the SCQ as:
- The xs compose something iff there is exactly one x or the activity of the xs constitutes a life.
But he doesn’t try to give an answer to the GCQ, and suspects an answer can’t be given.
It is now seeming to me that van Inwagen should give a parallel answer to GCQ as well:
The x compose y iff the xs compose* y.
The xs compose* y iff every one of the xs is a part* of y and everything that overlaps* y overlaps* at least one of the xs.
x overlaps* y iff x and y have a part* in common.
x is a part* of y iff x = y or x’s activity constitutes engagement in the life of y.
Here, (3) and (4) mirror the standard mereological definition of composition and overlap, but with asterisks added. The asterisked concepts, however, bottom out in non-mereological concepts.
One might worry that constitution is a mereological concept. But if it is, then van Inwagen’s answer to the SCQ is also unsatisfactory because it uses constitution.
I feel that (2)–(5) might have some simple counterexample, but I can’t see one (or at least not one that isn't also a counterexample to van Inwagen's answer to the SCQ).
By the way, there is a cheekier answer to the GCQ:
- The xs compose y iff the xs and y satisfy the predicate “composes” of the actual world’s late 20th century philosophical English language.
Note that here the response does not make any use of mereological vocabulary, since “‘composes’” (unlike “composes”) is not a piece of mereological vocabulary, but a piece of metalinguistic vocabulary.
